1. Field of the Invention
This invention relates to heat exchange units for use in an air conditioning system. Particularly this invention relates to a combination cover and grille for use with the outdoor heat exchange unit of a heat pump or the condenser unit of a cooling system or a packaged system.
2. Description of the Prior Art
Air conditioning systems for conditioning residences and other interior spaces frequently utilize a combination of components such that the condenser unit of an air conditioning system is located outside of the residence and the evaporator unit of the system is located in communication with the interior space to be cooled. In a heat pump application the system might have an outdoor heat exchange unit located without the enclosure and an interior heat exchange unit in communication with the interior space to be conditioned. These systems further utilize a compressor and appropriate expansion valves and piping such that heat may be transferred either to the region to be heated or from the region to be cooled. Each outdoor unit has an electric motor and fan associated therewith such that outdoor air may be drawn through the heat exchanger of the unit. This air typically flows through a grille either entering the unit or being discharged from the unit.
The proper mounting and operation of the unit is very important because of the operation of the air conditioning system depends upon the capability of the heat exchanger located in the outdoor unit to transfer heat to or from the air. Furthermore, the outdoor location of the fan and motor renders it susceptible to various sorts of damage. For example, the operation of the fan motor can be seriously impaired if moisture or dirt enter the motor bearings. The likelihood of such damage is greater in those units wherein the fan shaft extends vertically upwardly since water can run down the shaft and through the bearings. Another type of problem to which these outdoor units are susceptible is movement of the fan assembly relative to the air discharge opening in the enclosure. The fan assembly has heretofore been attached either directly to the enclosure or to legs fastened to the enclosure walls. These supports for the fan assembly can be distorted during shipment of the unit to the installation site or after the unit has been installed in its outdoor location. Movement of the fan assembly relative to the discharge opening housing changes the path of flow through the opening, generally resulting in reduction of the air flow rate. In addition, the incorporation of the foregoing types of motor mounts requires an expense whose removal or reduction would be advantageous.
Typical of the previous motor mounting systems utilizing a grille is U.S. Pat. No. 3,865,517 assigned to the assignee herein. Therein a grille is formed from a series of circular shaped members to prevent objects from entering the heat exchange assembly while maintaining sufficient openings to allow for the movement of air therethru. Other patents involving grille assemblies and motor mounting means include Trask (U.S. Pat. No. 2,920,464), Day (U.S. Pat. No. 3,115,757) and Fowell et al (U.S. Pat. No. 3,714,795). All of these patents relate to means for mounting motors in reference to the fan and grille for air discharge.
The present invention relates to a unitary single piece. The top cover with stamped radial open louvers simultaneously serves as a grille and motor mount. The louvers are inclined sections of adjacent radially extending segments. The degree of inclination of the louvers is matched with the inclination characteristics of the fan blade such that these louvers act to optimize the air flow of the fan for a certain amount of energy input into the motor. None of the above referenced patents discloses using a unitary stamped air grille cover nor do they disclose using the design of the grille to optimize the air flow characteristics of the fan. Furthermore the center portion of the grille serves to protect the fan motor and bearings from the elements eliminating the need for a rain shield or other protective covering for the motor.